Intermodal chassis

ABSTRACT

An intermodal chassis for highway transportation of shipping containers, the chassis having a forward axle and a rear axle, and incorporating an air bag suspension that automatically deflate the air bags when the brakes are locked, preventing damage when loading a container onto the chassis. Large 53 foot long box/high cube type shipping containers may be loaded along their entire length with the chassis having a rear axle positioned under the chassis frame so that the kingpin-to-rear-axle length is no more than 40 feet, and a forward axle positioned under the frame between the gooseneck and the rear axle so that a forward-to-rear-axle length is at least 12 feet. Other features include self-scaling and load-leveling, and other weight savings include use of smaller sized aluminum wheels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/923,440 filed on Oct. 27, 2015, now U.S. Pat. No. 9,908,453 issued onMar. 6, 2018, which claims the benefit of U.S. provisional applicationSer. No. 62/069,147 filed on Oct. 27, 2014, the entireties of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The technical field of the invention pertains generally to intermodalchassis designs, and, more particularly, to improvements in anintermodal chassis especially suited for 53 foot domestic use intermodalcontainers and that provides for improvements in load capacity and easeof use, while meeting state specific transportation regulations.

Intermodal chassis are semi-trailers used for hauling intermodalshipping containers over the road. Intermodal shipping containers areused for shipping product via road, rail, or ocean. The 53 foot (53′)shipping container is also referred to as a “long box” shippingcontainer, or a “high cube” container because it provides expansivecapacity with a typical height of (9′6″) 114″, width of (8′6″) 102″, andlength of 53′. This is 1 foot taller than standard height containers.Another common container length is 48′. International shipmentstypically utilize intermodal containers that are 6″ narrower andtypically either 20′ or 40′ in length.

The 53′ intermodal long box container is the most common type ofcontainer used for domestic shipping within the United States. The 53′container was constructed and introduced primarily for domesticover-the-road/highway and railroad shipping. 53′ containers aretypically constructed of 14-gauge (14 Ga) corrugated steel throughout,with 1⅛″ thick marine plywood flooring on the interior.

A typical intermodal chassis for a 53′ container consists of front andrear bolsters which engage with the lower edges at the front and rear ofthe container, with a frame extending between and interconnecting thefront and rear bolsters, tandem axles positioned toward the rear of thechassis, and a forward portion of the chassis near the front bolsterthat has a raised surface section sized to fit within a correspondingtunnel depression (3⅛″ deep) section on the underside of the container.The typical intermodal chassis is constructed of steel, with a standardleaf spring type suspension, standard sized steel hub wheels (8¼″×22.5″hub), and standard sized tires (11R22.5 tire). The kingpin forconnection with the fifth wheel of a towing tractor is typically setback from the rear face of the bolster by 36″.

The 53′ long box/high cube containers typically require careful loadingarrangements to achieve load balancing and distribution between thefront nose of the container and locations within the container forwardof the chassis tandems, in order to meet particular state highwaytransportation regulations (or so-called bridge laws). For example, FIG.1 shows a side view 100 of a typical truck 104 and semi-trailer 102loading arrangement for meeting California Department of Transportationregulations. The kingpin-to-rear-axle (KPRA) length 108 must not exceeda length of 40 feet. Commercial vehicles may not exceed 80 k lbs GVW.Axle restrictions include a limit of 34 k lbs on the drive tires 112, 34k lbs on the tandem tires 114, and 12 k lbs on the steer tires 110. Tomeet these requirements, the typical semi-trailer 102 needs to havecargo 106 arranged to be secured forward of the rear tandems 114,keeping product between the tandem axles 114 and the nose or front ofthe container. Carriers are advised to load heavier pallets in the noseof the container closer to the tractor cab 104, followed by lightpallets and then the lightest pallets rearward, yet still forward of therear most axle. As shown in FIG. 1, the result is empty(unused/unusable) space in the container aft of the rear tandems 114.Moreover, substantial effort and care is needed to distribute the weightwithin the container from left side to right side and from the nose ofthe container space to the rear most position of pallets and product,often using inflatable air bags or other dunnage (not shown) tostabilize separation and spacing of pallets and product. Because loadsneed to be scaled at the origin of a particular route (to ensure theload is legal for the destination state), considerable care is needed toproperly load the cargo 106 into the trailer 102.

What is needed, therefore, are improved intermodal chassis designs thatprovide for improvements in load capacity, cost of operation, and easeof use, and that adhere to state specific transportation regulationssuch as those established by the California Department of Transportationthat apply to over highway shipping using 53′ intermodal containers.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS

For a more complete understanding of the present invention, the drawingsherein illustrate examples of the invention. The drawings, however, donot limit the scope of the invention. Similar references in the drawingsindicate similar elements.

FIG. 1 is a side view showing a typical semi-tractor and trailer loadingarrangement for meeting California Department of Transportationregulations.

FIG. 2 is a side view of an improved intermodal chassis that allows forincreased loading capacity, according to various preferred embodiments.

FIG. 3 is a top view of the improved intermodal chassis in FIG. 2,according to preferred embodiments.

FIG. 4 is a perspective view of the improved intermodal chassis in FIGS.2 and 3 as viewed from above and the rear and passenger side, accordingto preferred embodiments.

FIG. 5 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the rear looking toward the front of thechassis, according to preferred embodiments.

FIG. 6 is a side perspective view of an axle portion of the improvedintermodal chassis in FIG. 4 as viewed from the driver side, accordingto preferred embodiments.

FIG. 7 is a side perspective view of the axle portion shown in FIG. 6 asviewed from the rear and driver side, according to preferredembodiments.

FIG. 8 is a perspective view of a gooseneck portion of the improvedintermodal chassis in FIG. 4 as viewed from above and the rear anddriver side looking forward toward the front of the chassis, accordingto preferred embodiments.

FIG. 9 is a perspective view of an axle portion of the improvedintermodal chassis in FIG. 4 as viewed from below and rear, according topreferred embodiments.

FIG. 10 is a perspective view of a forward portion of the improvedintermodal chassis in FIG. 4 as viewed from above and rear lookingforward toward the front of the chassis, according to preferredembodiments.

FIG. 11 is a perspective view of an axle portion of the improvedintermodal chassis in FIG. 4 as viewed from above and rear, according topreferred embodiments.

FIG. 12 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the rear and driver side, according topreferred embodiments.

FIG. 13 is a perspective view of a landing gear portion of the improvedintermodal chassis in FIG. 4 as viewed from below and the front anddriver side looking rearward toward the back of the chassis, accordingto preferred embodiments.

FIG. 14 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the rear looking toward the front of thechassis, according to preferred embodiments.

FIG. 15 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the front looking toward the back of thechassis, according to preferred embodiments.

FIG. 16 is a front elevation view the improved intermodal chassis inFIG. 4, according to preferred embodiments.

FIG. 17 is a rear elevation view the improved intermodal chassis in FIG.4, according to preferred embodiments.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the preferredembodiments. However, those skilled in the art will understand that thepresent invention may be practiced without these specific details, thatthe present invention is not limited to the depicted embodiments, andthat the present invention may be practiced in a variety of alternateembodiments. In other instances, well known methods, procedures,components, and systems have not been described in detail.

Although preferred embodiments are presented and described in thecontext of an improved intermodal chassis design especially suited for53 foot domestic use intermodal containers, numerous separable inventiveaspects are presented that may be used in a wide variety of otherover-the-road cargo hauling applications and with the use of a widevariety of other types (and sizes/lengths) of intermodal containers andfreight hauling trailers (including 53′ length flatbed or other typesand lengths of trailers).

The present inventor(s) discovered new, unique, and truly innovativemethods, systems, and apparatus for improving an intermodal chassisdesign especially suited for 53 foot intermodal containers. Variousembodiments are illustrated and described in the figures, sketches,details, descriptive materials, and pictures submitted in incorporatedby reference herewith. The various embodiments include separableinventive aspects which are separately patentable. The listed inventiveaspects are not exhaustive or comprehensive, and further/additionalseparable inventive aspects are included in the submitted materials butmay not be specifically or particularly identified or described in wordsdue to the need to capture (in many instances in detailed illustrations,pictures, or sketches) the many separable inventive aspects in thisdisclosure.

The present inventors invented an intermodal chassis that allowsshippers to ship more freight into and out of the state of Californiavia the railroad using stack train intermodal containers while complyingwith California vehicle bridge weight limitations. Loads into and out ofNevada are also affected by California bridge laws because the actualrail terminal is in California.

The chassis invented, prototyped, and tested helps shippers withproducts which occupy most of the cube of a 53 foot intermodal containerutilize the entire 53 foot container space without having to cut palletsoff at the rear of the container to meet the bridge law restrictions inCalifornia. Most shippers with freight weighing 38500 to 43500 lbs andhaving high cube requirements are the shippers which have to reduce thequantity of pallets loaded in order to meet the bridge laws.

Dense shippers currently must load loads in a configuration whereby theaxles are equalized and airbags or other dunnage are required to secureand spread the load, for example, as shown in FIG. 1. Using the presentinventors' chassis reduces dunnage costs and damage by allowing theentire 53 foot container space to be utilized and allowing for morefreight to comprise the load before maxing out due to weight.

The present inventors' determined that the directions from majorintermodal companies direct shippers as to how to load trailers so thatthe California bridge law is not violated comprises legalizing the loadby configuring the load differently and spreading weight out. High cubeshippers, the present inventors' found, are not able to effectively usethis measure because the trailer is filled with product. The majorintermodal companies limit the maximum gross weight of the load to 43500lbs. By comparison, the present inventors' improved intermodal chassisdesigns allow for the container to be loaded to a maximum of 47500 lbs.

As will be described further in the figures, the present inventorsdiscovered numerous improvements that, when combined in preferredembodiments, provide for improved load capacity, lowered cost ofoperation, and greater ease of use, while solving problems of meetingthe bridge law requirements.

The present inventors discovered major improvements in load distributionare achieved by separating the axles so that a forward positioned axleis at least 12 feet forward from the rear most (second) axle instead ofusing a standard pair of tandem axles. The separation between the axles,it was discovered, spreads the load, and the axles are counted asseparate axles as opposed to tandem axles for purposes of calculatingbridge loading and in compliance with the California bridge laws.

The present inventors discovered a dramatically lighter weight chassisframe design by strategically cutting circular holes from key portionsof the chassis frame structure in areas where the material was notneeded to maintain sufficient integrity and strength. The strategicallyplace cutouts, the present inventors discovered, allows better fueleconomy, reduced chassis weight, and increased available load weight.

Existing chassis designs use springs and not air bags because lowering acontainer onto the chassis effectively suddenly loads each of theforward and rear axles with 40,000 pounds, which would break the airbags. The present inventors discovered that bleeding out the air bags sothat the frame rests all the way down on the axles such that the only“give” is pressure in the tires, works to avoid blowing out the airbags. To overcome the problems of bursting the air bags of thesuspension when loading the container onto the chassis, the presentinventors discovered automatically deflating the air bags when thechassis trailer brakes are locked prevented damage to the bags from harmwhen a container is dropped to quickly.

The present inventors discovered that replacing the standard springsuspension with a deflatable air ride suspension also achieved weightreduction and allows the driver to adjust the height of the container(being hauled on the chassis) to match differing dock heights. The newdesign provides a load leveling functionality not available in existingintermodal chassis designs. The driver is able to raise the load up todock level or lower it down, by adjusting the amount of air in the airbags.

The present inventors discovered using smaller wheels, such as 19.5 inchwheels, achieves weight reduction, allows for lower height positioningof the chassis (due to lower axle height), and also reduces theft ofchassis tires and wheels because the 19.5 sized wheels do not fit commontruck trailers or other chassis.

The present inventors discovered further weight reduction by usingaluminum wheels instead of typically used steel wheels. Importantly,reduction of weight at the wheels (as also for weight reductionsassociated with using air bag suspension instead of springs) providesfor higher gross payload overall and weight latitude on specific axles.

The present inventors discovered that using air bags in the suspensionallows for self-scaling and distribution of weight longitudinally toadjust weight over a given axle. Previously, the container would beloaded using best guessing, and the drive would hope it's legal untilthe driver is able to stop at a public scale. The risk is gettingstopped with an improperly distributed load. Shippers do not typicallyhave their own scales, so there are few ways to avoid this risk. Withself-scalers integral to the chassis, which employ the air bags withhydraulics, the problem is addressed. The present inventors discoveredthat providing for the chassis to be self-scaling enables the driver todetermine whether a load is leaving the yard in a legal fashion withoutgoing to a public scale, thus reducing the costs of scaling andpotentially expensive highway fines for improperly balanced oroverloaded conditions.

The present inventors discovered that adjustments in the location of thekingpin on the chassis from a standard 36″ aft of the rear face of thefront bolster to positions incrementally rearward toward a position at48″ aft of the rear face of the front bolster allows for more load to beplaced in the nose of the container, thereby over the drive axles andincreasing weight on the tractor.

The present inventors discovered using Teflon plates instead of thetypical steel with grease applied, achieves cost savings in maintenanceand reduces overall wear and tear. In one embodiment, the pickup plateis coated with a non-stick, self-lubricating material, and grease orother lubricants are unnecessary.

The present inventors discovered incorporating LED lighting reducespower consumption, improves lamp life, and improves safetycharacteristics of the chassis since LED lights are brighter, requireless power, and last many times longer than the standard incandescentbulbs used on existing intermodal chassis designs.

FIG. 2 is a side view 200 of an improved intermodal chassis 202 thatallows for increased loading capacity, according to various preferredembodiments. The left side or driver side of the chassis 202 is shown,with a front bolster 230 at a forward end and a rear bolster 228 (andrear bumper 226 therebelow) at a rearward or rear most end of thechassis, the two bolsters longitudinally interconnected by framestructure comprising a gooseneck portion 232 with a top surface 218extending rearward from the front bolster 230, and a main frame steppeddown top surface portion 224 extending from the gooseneck portion 232rearward to and including the rear bolster 228. The raised gooseneck topsurface 218 is preferably sized to fit within the correspondingdepression or tunnel formed in the lower surfaces of the nose/front of astandard intermodal container. In one embodiment, the gooseneck topsurface 218 is offset from the main frame top surface 224 by 3⅛″. Thelength (206 to 204) between the front of the chassis 206 and the rearend 204 of the rear bolter 228 is preferably 53′ 8⅞″.

Just aft or rear of a transition from the gooseneck top surface 218 tothe main frame top surface 224 is an extendable jack stand or landinggear 220, with sand shoes 22 for ground contact. Extending rearward arepreferably two axle/wheel/tire assemblies—a forward traileraxle/wheels/tires assembly 208 and, separated rearward, a rear traileraxle/wheels/tires assembly 210. In preferred embodiments, the verticallyextendable landing gear 220 comprise a pair of sand shoes 222, and eachof the axle/wheels/tires assemblies 208 and 210 comprise an axle withwheels and tires. In preferred embodiments, the wheels comprise aluminumhubs and are smaller sized than standard semi trailer wheels, preferablycomprising 19.5 inch wheels to provide a lower axle to ground height,thus allowing the chassis to be lowered to a lower height, and toprovide weight reduction. The ground-to-main frame top surface 224height is preferably nominally 48″ in normal operating conditions.

Several holes 214, 216, 212 are preferably strategically cut within thesides of the main frame for weight reduction, preferably similarly sized(for example, each having a diameter of 5″) and arranged in pairs, withtwelve (12) holes in each main (I-beam) side, as shown.

FIG. 3 is a top view 300 of the improved intermodal chassis 202 in FIG.2, according to preferred embodiments. In preferred embodiments, thecenter of the forward axle 310 and the center of the rear axle 308 areseparated by at least twelve (12) feet so that each axle is considered aseparate axle. In one embodiment the spread between the center of theforward axle 310 and the center of the rear axle 308 is 12′1″ (twelvefeet, one inch). In preferred embodiments, the distance between thecenter of the kingpin (not shown) and the center of the rear axle 308 isjust under 40′ to comply with state regulations. In one embodiment, thekingpin mount 338 is 40.25″ from the rear surface of the front bolster230, and the position of the rear axle 308 is set to be just under the40′ kingpin-to-rear-axle (KPRA) limit. In other embodiments, the kingpinmount 338 may be positioned rearward from between 36″ toward 48″ aft ofthe rear surface of the front bolster 230, with an increasingly rearwardmounting position putting more weight on the tractor drive tires.

The front or gooseneck portion 232 of the chassis 202 preferablycomprises gooseneck I-beams 332 and 330 arranged in parallel andinterconnected to one another by cross members such as gooseneck(tubular) cross members 334 and 336. The gooseneck I-beams 332 and 330extend rearward from the front bolster 230 and transition to mainI-beams 302 and 306 comprising a main frame portion of the chassis 202,with the main I-beams 302 and 306 extending rearward from the gooseneckportion 232 past the landing gear 220, front and rear axles 310 and 308,respectively, and ending at the rear bolster 228. Various cross memberssuch as (tubular) cross members 324, 322 and diagonal (C-channel) crossmembers 328, 326 (and other cross members not numbered) interconnect themain I-beams 302 and 306, which, as shown in FIG. 3, are parallel to oneanother and longitudinally aligned with the gooseneck I-beams 332 and330. In preferred embodiments, five (5) diagonal cross members such as328 and 326 provide bracing in five (5) bays along the main framebetween the landing gear 220 and forward and rear axles.

In preferred embodiments, air lines and electrical wires (not shown) arerouted along the length of the chassis 202, and at least one air tank(not shown) is mounted (such as in the location marked 320) foroperation of air bags associated with the suspension for each of theaxles 310 and 308 and corresponding wheels and tires—right (passenger)side forward tires 318, left (driver) side forward tires 316, right(passenger) side rear tires 314, and left (driver) side rear tires 312.Although each axle 310 and 308 is shown with a set of four (4)wheels/tires, further weight reduction may be achieved using two (2)double (or fat) wheels/tires for each axle. For example, one doublewheel/tire may be used in place of the right side forward pair of tires318, that are configured and sized to provide similar ground contact andother characteristics, and likewise for the pairs of tires 316, 314, and312.

In preferred embodiments, the width of the rear bolster 228 from left(driver) side to right (passenger) side is 96¾″ and the width of thebumper 226 from left side to right side is 88¾″. The outward ends of thetop surface of the rear bolster 228 preferably comprises attachmentpoints or (ISO) twist locks 304 to securely fasten with correspondinglyformed corner castings of a standard intermodal container.

FIG. 4 is a perspective view 400 of the improved intermodal chassis 202in FIGS. 2 and 3 as viewed from above and the rear and passenger side,according to preferred embodiments. As shown, air bags 402, 404 arepreferably used for suspension instead of typically used leaf springsuspension systems. In preferred embodiments, the air bags are deflatedto prevent damage to the air bags when a container is loaded onto thechassis 202. Preferably, the air bags automatically deflate when thechassis brakes are locked. In various embodiments, the driver/operatormay adjust the amount of air in the air bags to adjust the level of thecontainer for loading and unloading of the container at, for example,dock surfaces that may vary in height, and the amount of air in the airbags may be adjusted to level the chassis for transport. The air bagsare preferably integrated into a self-scaling systems whereby the amountof air in the air bags, the pressure within the air bags, and/ormeasures of position and degree of inflation are used for determinationof load weight over each of the forward and rear axles.

In preferred embodiments, the front bolster 230 comprises formed 10 Ga1020 steel sheet metal, the rear bolster 228 comprises 7 Ga wall 1020steel 8″ square tube, the rear bumper 226 comprises horizontal 3″ by 4″7 Ga wall 1020 steel tube and vertical ¼″ wall 1020 steel 3″ squaretube, the main I-beams 302, 306 comprise 0.24″ thick 1020 steel 11.8″tall 4″ flats (top and bottom), the gooseneck I-beams 330, 332 comprise0.25″ thick 1020 steel 4.25″ tall 4.25″ flats (top and bottom), thecross members comprising 1020 steel tube or formed sheet. In preferredembodiments, the chassis I-beams, cross members, bolsters, and otherreinforcements, bracing, and brackets are welded together and thenpainted. In one embodiment, an experimental use prototype wasconstructed by the present inventors—having substantially thecharacteristics shown in FIG. 4, including smaller aluminum wheels, airbag system, forward and rear axles spread apart at least twelve feet,and 5″ diameter holes cut in the main I-beams and cross members asshown—with an unladen weight (as licensed/registered with California) at2915 lbs.

FIG. 5 is a perspective view of the improved intermodal chassis 202 inFIG. 4 as viewed from above and the rear looking toward the front of thechassis, according to preferred embodiments. The chassis 202 preferablyincorporates LED lighting 502 within the rear bolster 228 between twistlock 304 locations.

FIG. 6 is a side perspective view of an axle portion 600 of the improvedintermodal chassis 202 in FIG. 4 as viewed from the driver side,according to preferred embodiments. And FIG. 7 is a side perspectiveview of the axle portion shown in FIG. 6 as viewed from the rear anddriver side, according to preferred embodiments. FIGS. 6 and 7 moreclearly show the separate forward axle 310 and rear axle 308, and theair bags associated with each—right rear air bag 404 and left rear airbag 702, for rear axle 308; and right forward air bag 402 and leftforward air bag 602, for forward axle 310. Also depicted more clearlyare holes 604 and 606 in the left side main I-beam 306, which preferablycomprise 5″ diameter cut outs arranged as shown.

FIG. 8 is a perspective view of a gooseneck portion of the improvedintermodal chassis in FIG. 4 as viewed from above and the rear anddriver side looking forward toward the front of the chassis, accordingto preferred embodiments. From the front bolster 230 extending rearwardand covering the lower surfaces under and between the gooseneck I-beams232, a pickup plate preferably fills the spaces 806, 808, 810, 812, and814 between the front bolster 230 and transverse channel 820, betweentransverse channel 820 and gooseneck tube 334, between gooseneck tube334 and gooseneck tube 336, and between gooseneck tube 336 andtransverse channel 816. Kingpin mounting 338 is preferably weldedbetween gooseneck tubes 336 and 334, as shown. Wing plates 802 and 804stiffen the outer ends of the front bolster 230. Three (3) transversechannel cross members 820, 816, and 818, along with three (3) goosenecktube cross members 334, 336, and 822 interconnect the right and leftgooseneck I-beams that provide the gooseneck top surface 218. Goosenecktransition tubes 824 and 826 angle downward to the forward face of agusset 832 that forms a bulkhead and start/forward most portion of theframe structure providing the main frame top surface 224 that extendsrearward all the way to the rear bolster 228. Formed flat bartransitions 828 and 830 (with welded insert panels, not numbered)provide a transition from the gooseneck I-beams 232 to the main frameI-beams 302, 306.

In preferred embodiments, the pickup plate (806, 808, 810, 812, 814)comprises one piece of sheet metal, smooth on its lower surface,exposing the kingpin mounted thereon, the kingpin extending downwardfrom the pickup plate for engagement with the receiver of a semi-tractorwhen the chassis is to be towed. The wing plates 804 and 802 preferablycomprise ¼″ thick 1020 steel. The front bolster 230 preferably comprisesformed 10 Ga 1020 steel sheet metal. The kingpin mount 338 preferablycomprises C-channel opened downward. The transverse channels 820, 816,and 818 each preferably comprise C-channel opening rearward. Thegooseneck tube cross members 334, 336, and 822 each preferably comprise3″ by 4″ 1020 steel rectangular tube with 0.25″ thick wall material. Thegooseneck I-beams 330 and 332 (also referenced as 232) preferablycomprise 0.25″ wall 1020 steel 4.25″ tall with 4.25″ top and bottomflats. The formed flat bar transitions 828 and 830 preferably comprise5″ wide 1020 steel bar stock.

FIG. 9 is a perspective view of an axle portion of the improvedintermodal chassis 202 in FIG. 4 as viewed from below and rear,according to preferred embodiments. As shown, the forward part of thechassis includes a cross support 902 between the non-extendable tubes ofthe landing gear 220. In preferred embodiments, the chassis 202comprises eight (8) wheels and tires, a pair of wheels and tires on theeach end of each axle. As shown, the forward axle 310 has an inner rightforward tire 904, an outer right forward tire 906, an inner left forwardtire 918, and an outer left forward tire 916. The rear axle 308 has aninner right rear tire 908, an outer right rear tire 910, an inner leftrear tire 914, and an outer left rear tire 912.

FIG. 9 also shows the main frame I-beams in more detail. The right sideI-beam is shown with (the underside of) a bottom flat 920 and (theunderside of) a top flat 922. The left side I-beam is shown with abottom flat 924 and a top flat 926. Preferably the I-beam comprises11.8″ tall 0.24″ thick 1020 steel with the top and bottom flats being 4″wide. The cross members 928, 930, and 932 shown interconnecting theright and left I-beams to form the main frame, preferably comprise 8″tall by 2″ longitudinally along the frame by 0.25″ thick 1020 steelrectangular tube.

FIG. 10 is a perspective view of a forward portion of the improvedintermodal chassis 202 in FIG. 4 as viewed from above and rear lookingforward toward the front of the chassis, according to preferredembodiments. The chassis 202 preferably comprises six (6) cross memberswelded to and interconnecting the two main frame I-beams that are formedand configured the same as the C-channel shaped cross member 1032. Theformed cross member 1023 preferably has three (3) cut outs 1002, eachmeasuring 5″ in diameter, and each comprises 0.375″ thick 1020 steelsheet metal formed to have a height of 9″, lower longitudinal width of3″, and an upper longitudinal width (at its right and left sides, wherethe cross member is welded to the inside surfaces of the main frameI-beams) of 7.5″. The three (3) five (5) inch holes are preferablyequally spaced from left to right, as shown. And the open part of theformed “C” channel is directed rearward. Each of six (6) similarlyformed cross members are preferably oriented in a similar way, includingcross members 1032, 1010, 1012, 1014, 1016, and 1018 (referencing thecross members from the rear of the chassis moving forward). The bulkheadgusset 832 shown in FIG. 8 is preferably formed to be similar to each ofthe six (6) formed cross members 1032, 1010, 1012, 1014, 1016, and 1018except without the three (3) cutouts. Preferably, each of the crossmembers 1030, 1028, 1026, 1024, 1022, and 1020 comprise the sameconstruction as described for rectangular tube cross members 928, 930,and 932 in FIG. 9. As shown in FIG. 3, one more cross member is shownbetween the formed cross member 1032 and the rear bolster 228, and thiscross member is preferably constructed to be similar to the otherrectangular tube type cross members 1030, 1028, 1026, 1024, 1022, and1020. Therefore, in preferred embodiments, there are seven (7)rectangular tube cross members and seven (7) formed cross membersinterconnecting the right main I-beam 302 and the left main I-beam 306.

Preferably, the five (5) diagonal cross supports 1004, 326, 328, 1006,and 1008 comprise C-channel 0.25″ thick 1020 steel, 3″ wide by 1.5″tall, with the open end directed downward. A side view as in FIG. 2would show each diagonal cross support as having a height of 1.5″. A topview as in FIG. 3 would show the width of each diagonal being 3″.

FIG. 11 is a perspective view of an axle portion of the improvedintermodal chassis in FIG. 4 as viewed from above and rear, according topreferred embodiments, and shows more clearly a relative positioning ofright and left rear shock absorbers 1104 and 1102, respectively. Asimilar shock absorber is configured for each of the four (4) air bags,as shown also in FIGS. 6, 7, and 9.

FIG. 12 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the rear and driver side, according topreferred embodiments, and shows the chassis 202 from the opposite sideand at less of a downward angle than illustrated in FIG. 4.

FIG. 13 is a perspective view of a landing gear portion of the improvedintermodal chassis in FIG. 4 as viewed from below and the front anddriver side looking rearward toward the back of the chassis, accordingto preferred embodiments. Preferably, holes 1322 and 214 are cut in thesides of the main I-beam 306 just aft of the landing gear 1302. Theholes 1322 and 214 preferably are 5″ diameter cutouts and are similarlysized as the other cutouts shown along main I-beams 306 and 302. Thelanding gear 220 preferably comprises non-extendable tubes 1302 and 1304from which telescopic members 1308 and 1306 may extend, each capped by asand shoe 1310, 1312. Stabilizer bracing 1316, 1318, and 1320 and alateral cross support 1314 are preferably used to further stiffen andsupport the landing gear 220.

FIG. 14 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the rear looking toward the front of thechassis, according to preferred embodiments. As shown from this angle,the wing plates 1402 and 1404 between the main I-beam outward sides andthe rear bolster 228 are visible.

FIG. 15 is a perspective view of the improved intermodal chassis in FIG.4 as viewed from above and the front looking toward the back of thechassis, according to preferred embodiments. FIG. 15 more clearly showsthe arrangement of cross members interconnecting the right and leftI-beams. Six (6) cross members comprise the gooseneck portion—three (3)transvers channel and three (3) gooseneck tube. Fourteen (14) crossmembers comprise the main frame portion—one bulkhead cross member at thegooseneck-to-main frame transition, followed by five (5) formed crossmembers with holes, followed by six (6) rectangular tube type crossmembers, followed by a sixth formed cross member with holes, and lastlya seventh rectangular tube cross member.

FIG. 16 is a front elevation view the improved intermodal chassis inFIG. 4, according to preferred embodiments. FIG. 17 is a rear elevationview the improved intermodal chassis in FIG. 4, according to preferredembodiments.

The terms and expressions which have been employed in the foregoingspecification are used therein as terms of description and not oflimitation, and there is no intention in the use of such terms andexpressions of excluding equivalents of the features shown and describedor portions thereof, it being recognized that the scope of the inventionis defined and limited only by the claims which follow.

What is claimed is:
 1. An intermodal chassis for carrying a shippingcontainer for over-the-highway transport, the chassis comprising: afront bolster and a rear bolster, with a frame structure extendinglongitudinally therebetween and sized to carry said shipping container;a gooseneck portion of said frame structure extending longitudinallyrearward from said front bolster and having a top surface sized to fitwithin a tunnel depression of said shipping container; a kingpin mountedon a bottom surface of said gooseneck portion rearward of a rear face ofsaid front bolster; a main portion of said frame structure extendinglongitudinally rearward from said gooseneck portion and interconnectingwith said rear bolster; a rear axle positioned longitudinally under saidmain portion of said frame structure; a forward axle positionedlongitudinally under said main portion of said frame structure betweensaid gooseneck portion and said rear axle; and air bag suspension forsaid forward and rear axles, with the air bags for each axle adapted toautomatically deflate when a chassis brake system is locked, therebyprotecting said air bags from damage when loading said container ontosaid chassis.
 2. The chassis of claim 1 further comprising aself-scaling system and a load-leveling system associated with said airbags.
 3. The chassis of claim 1 wherein said shipping container is a 53foot long box/high cube type container.
 4. The chassis of claim 1wherein said kingpin mounted is on said bottom surface of said gooseneckportion at a position between 36 inches and 48 inches rearward of saidrear face of said front bolster.
 5. The chassis of claim 1 wherein saidforward axle is positioned longitudinally under said main portion ofsaid frame structure between said gooseneck portion and said rear axlesuch that a forward-to-rear-axle length is at least 12 feet.
 6. Thechassis of claim 1 further comprising multiple holes cut from said framestructure to reduce the weight of said chassis.
 7. The chassis of claim1 further comprising only 19.5 inch wheels to reduce the height of saidforward and rear axles and to reduce the weight of said chassis.
 8. Thechassis of claim 1 wherein said wheels comprise aluminum instead ofsteel to reduce the weight of said chassis.
 9. The chassis of claim 1further comprising non-stick, self-lubricating material on said bottomsurface of said gooseneck portion proximate to said kingpin.
 10. Thechassis of claim 1 further comprising LED lights integrated into a rearfacing surface of said rear bolster.
 11. An intermodal chassis adaptedfor carrying a 53 foot long box/high cube type shipping container thatis loaded with cargo along its entire 53 foot length, forover-the-highway transport, the chassis comprising: a front bolster anda rear bolster, with a frame structure extending longitudinallytherebetween and sized to carry said 53 foot long box/high cube typeshipping container; a gooseneck portion of said frame structureextending longitudinally rearward from said front bolster and having atop surface sized to fit within a tunnel depression of said shippingcontainer; a kingpin mounted on a bottom surface of said gooseneckportion at a position between 36 inches and 48 inches rearward of a rearface of said front bolster; a main portion of said frame structureextending longitudinally rearward from said gooseneck portion andinterconnecting with said rear bolster; a rear axle positionedlongitudinally under said main portion of said frame structure such thata kingpin-to-rear-axle length is no more than 40 feet; and a forwardaxle positioned longitudinally under said main portion of said framestructure between said gooseneck portion and said rear axle such that aforward-to-rear-axle length is at least 12 feet, the combination of saidkingpin position, said kingpin-to-rear-axle length, and saidforward-to-rear-axle length allowing said chassis to carry said 53 footlong box/high cube type shipping container with said container loadedwith cargo along its entire 53 foot length and free from reducing cargoweight positioned rearward of said rear-axle.
 12. The chassis of claim 1further comprising air bag suspension for said forward and rear axles,with the air bags for each axle adapted to automatically deflate when achassis brake system is locked, thereby protecting said air bags fromdamage when loading said container onto said chassis.
 13. The chassis ofclaim 12 further comprising a self-scaling system and a load-levelingsystem associated with said air bags.
 14. The chassis of claim 11further comprising multiple holes cut from said frame structure toreduce the weight of said chassis.
 15. The chassis of claim 11 furthercomprising only 19.5 inch wheels to reduce the height of said forwardand rear axles and to reduce the weight of said chassis.
 16. The chassisof claim 15 wherein said wheels comprise aluminum instead of steel toreduce the weight of said chassis.
 17. The chassis of claim 11 furthercomprising non-stick, self-lubricating material on said bottom surfaceof said gooseneck portion proximate to said kingpin.
 18. The chassis ofclaim 11 further comprising LED lights integrated into a rear facingsurface of said rear bolster.